I didn't go to many product demos today, but I saw so many SOA talks it got pretty tiring (especially since most presenters hadn't seen the other presentations, so spent a long time going over things that had been discussed in depth elsewhere.)

I did pick up a few tips, though – mostly things that seem obvious in retrospect, but were expressed quite nicely:

• Reference Data should be versioned, and once versioned it should never change. This means that properly referenced version data can be cached without needing to think about cache invalidation.
• Having a big Web Service which takes various commands is a bad pattern, because it makes it more difficult to guarrentee an unchanging service contract
• There was a lot of discussion about canonical schemes for data (eg: the correct way to represent a customer or order object) and how to convert between canonical schemes and internal representations. (It's less work overall to convert-on-write, but reader-makes-correct is a valid system which can mean less data is lost).

The Tech Ed party is tonight, which should be good.